As is known, in the production of knitted articles for forming items of clothing, particularly of the type of body suits and bras, with circular knitting machines it is necessary to form pouch-like regions, for example for forming the cups of a bra. The need to provide pouch-like regions, in order to adapt the shape of the article to its particular use or simply to achieve merely aesthetic effects, is felt also in the production of articles to be used for the production of other items of clothing, such as for example undershirts, sleeveless tops, underpants, et cetera.
Currently, pouch-like regions on tubular articles produced with circular knitting machines are obtained, in some cases, by varying the tightness of the knitting. In other cases, the pouch-like regions are obtained by making a set of needles knit at one or more feeds or drops of the machine while the other needles remain unused during the actuation of the needle cylinder with a continuous rotary motion about its own axis, so as to produce, by means of said set of needles, rows of knitting in excess with respect to the rows of knitting formed by the other needles and by necessarily cutting the thread or threads used to form these excess rows of knitting proximate to the last needle of the set of actuated needles.
In other cases, a combination of these two knitting methods is put into practice and/or highly extensible threads are used in order to enhance shaping and improve the fit of the item of clothing.
These refinements do not fully meet the various requirements, since a variation in the tightness of the knitting determines a variation of the degree of transparency of the item of clothing, while making a set of needles knit while the other needles remain inactive, by requiring cutting of the thread used to produce the excess rows, has negative effects on the degree of finish of the item of clothing and on its fit.